1594  Energy-Aware Design Considerations

1594.1 Overview

Energy awareness is fundamental in IoT design. The difference between a device lasting weeks versus years depends entirely on careful attention to energy consumption at every level: component selection, circuit design, firmware implementation, and communication strategies.

This comprehensive guide is organized into focused chapters covering all aspects of energy-aware IoT design:

1594.2 Chapter Guide

1594.2.1 Foundations

  1. Introduction and Fundamentals
    • Why energy is the fundamental limiting resource
    • Power vs. energy concepts
    • The battery technology gap
    • Key design tradeoffs
  2. Energy Sources
    • Battery chemistries and selection
    • Primary vs. secondary batteries
    • Energy harvesting technologies overview
    • Capacity calculation and sizing

1594.2.2 Analysis and Optimization

  1. Power Consumption Analysis
    • Power state analysis
    • Average current calculation
    • Radio power states
    • Protocol energy comparison
    • Power budget worked examples
  2. Energy Cost of Common Operations
    • Digital operation energy hierarchy
    • The million-to-one rule
    • Communication vs. computation tradeoffs
    • Algorithm and data type optimization
  3. Low-Power Design Strategies
    • Sleep mode implementation
    • Duty cycling strategies
    • Peripheral power management
    • Voltage and frequency scaling
    • Communication optimization

1594.2.3 Measurement and Validation

  1. Energy Measurement and Profiling
    • Measurement tools and techniques
    • Shunt resistor method
    • Power profiler usage
    • Interpreting power profiles
    • Validating battery life predictions

1594.2.4 Advanced Topics

  1. Energy Harvesting Design
    • Solar panel sizing
    • MPPT implementation
    • Supercapacitor selection
    • Thermoelectric and piezoelectric harvesting
    • Channel capacity limits

1594.2.5 Practical Application

  1. Hands-On Lab: Power Monitoring
    • Wokwi simulation exercises
    • ESP32 deep sleep implementation
    • Wake-up source configuration
    • Optimization challenges
  2. Interactive Tools
    • Power budget calculator
    • Battery life estimator
    • Energy breakdown visualization
    • Auto-grading quiz
  3. Case Studies and Best Practices
    • Smart agriculture sensor optimization
    • Design phase best practices
    • Common pitfalls to avoid
    • Comprehensive review

1594.3 Quick Reference

1594.3.1 Target Specifications

Application Battery Life Target Max Avg Current
Field Sensor 5-10 years 50 ยตA
Smart Agriculture 2-5 years 100 ยตA
Wearable 1-7 days 5-20 mA
Smart Home 1-2 years 200 ยตA

1594.3.2 Key Formulas

Average Current: \[I_{avg} = \frac{I_{active} \times T_{active} + I_{sleep} \times T_{sleep}}{T_{cycle}}\]

Battery Life: \[Life = \frac{Capacity \times Efficiency}{I_{avg}}\]

1594.3.3 The Million-to-One Rule

Transmitting 1 byte over wireless costs approximately the same energy as 1 million 32-bit CPU operations. Always process locally when possible.

1594.5 Get Started

Begin with the Introduction and Fundamentals to understand why energy efficiency is critical, then proceed through the chapters in order or jump to specific topics based on your needs.